PHP 4.0 Bug #6913: wrong use of C language, serious bug!

From: Date: Thu, 28 Sep 2000 01:47:32 +0000
Subject: PHP 4.0 Bug #6913: wrong use of C language, serious bug!
Groups: php.dev 
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From: melchers@cis.fu-berlin.de Operating system: IRIX-6.x PHP version: 4.0.2 PHP Bug Type: Sockets related Bug description: wrong use of C language, serious bug! file ext/standard/file.c contains the line: if ((*buf = FP_FGETC(socketd, (FILE*)what, issock)) == EOF) { this is a _serious_ bug, since on _all_ machine architectures where the data type "char" defaults to unsigned, the return value of FP_FGETC() is converted to unsigned, before it is compared to EOF. Since EOF is defined as (-1), the comparison _never_ succedds. This makes any usage of sockets and file-I/O on "unsigned char" architectures impossible. As far as i remember, the bug occurs in all php versions, i.e. 3.x and 4.x. my page for fgetc(3) says: WARNING If the integer value returned by getc, getchar, or fgetc is stored into a character variable and then compared against the integer constant EOF, the comparison may never succeed, because sign-extension of a character on widening to integer is machine-dependent.

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